The broad research objectives are concerned with investigations at the molecular-biochemical level of the mechanism of RNA tumor virus replication and cell transformation. (a) Transcription in vitro of 60S virus RNA catalyzed by purified AMV reverse transcriptase with particular emphasis on obtaining large DNA products biologically active from oncornavirus RNA. Large DNA transcripts will be used to synthesize double-stranded "DNA provirus" which could be used in structural studies with known sequence specific restriction enzymes. BIBLIOGRAPHIC REFERENCE: Bolognesi, D., Collins, J., Leis, J., Moennig, V., Schafer, W. and Atkinson, P. The Role of Carbohydrate in Determining the Immunochemical Properties of the Major Glycoprotein of Friend Murine Leukemia Virus (gp71). J. Virol. 16:1453 (1975).